This invention relates generally to thermal protective devices for recessed lighting fixtures and, more particularly, to an arrangement for mounting such thermal protective devices on recessed lighting fixtures.
It has been recognized in the lighting industry that lighting fixtures mountable on ceiling or wall surfaces, especially those designed to be recessed in such surfaces, may become a fire hazard under certain circumstances. Fires have been known to occur when too large wattage lamps are used in the lighting fixtures and/or where insulation surrounding the fixture prevents heat produced by the fixture from properly dissipating.
To aid in the prevention of fires caused in the aforementioned manner, thermal protective devices, which interrupt current to the lighting fixture when overheating in the area surrounding the fixture occurs, are being employed. The need for such thermal protective devices in lighting fixtures, especially recessed fixtures, has been recognized by safety organizations, such as, for example, Underwriters Laboratory and the National Fire Prevention Association. Underwriter's Laboratory has issued specific standards for the operation of thermal protective devices used in recess mounted lighting fixtures.
One such type of thermal protective device designed for use in lighting fixtures is illustrated in U.S. Pat. No. 4,314,223, issued Feb. 2, 1982, in my name and assigned to the same assignee as the instant application. Thermal protective devices of the type described in the last-mentioned patent and similar devices are being employed in conjunction with recess mounted and other lighting fixtures with success in the prevention of overheating thereof.
One drawback associated with the use of a thermal protective device in conjunction with a recess mounted lighting fixture, is the placement of and manner in which to mount the device on the fixture. A desirable location for mounting a thermal protective device is in the interior of the lighting fixture housing or "can" received in the ceiling or other support surface. However, in such location, an increase in temperature of the environment surrounding the housing may be difficult to sense. The thermal protective device is, however, protected from damage which could occur if the device were mounted outside the housing. Rather than permitting the thermal protective device merely to be suspended in the housing where it could interfere with the lamp and other instrumentalities of the fixture as well as become damaged itself, it has been determined that it would be advantageous to mount the device directly on the inner surface of the side wall of the housing at a predetermined location therealong. A mounting arrangement to accomplish the latter would, however, need to be one which would permit proper sensing of the temperature surrounding the fixture, be simple to use, yet efficient and relatively inexpensive to produce.